This request is for partial funds to purchase a Leica TCS NT confocal microscope. This instrument will serve as the primary confocal microscope within the Center for Biologic Imaging (CBI) at the University of Pittsburgh Medical School. The mandate of this core facility is to provide access to a full range of light and electron optical, image analysis, and morphometric methods to all research groups within the medical area. The current confocal microscope (CLSM) within the facility is a 5 year old Molecular Dynamics Multiprobe 2001. Over the last two years it has become apparent to the steering committee of the CBI that this microscope is inadequate in terms of both technology and availability of instrument time. The specific technical concerns of users are that; the instrument is extremely slow, is equipped only with an argon laser, has poor Z axis stage control, low sensitivity photomultipliers, a poor optical transfer function, and a difficult user interface. The requested instrument provides fast high resolution, high sensitivity scanning with 3 separate lasers (argon, krypton, HeNe), coupled with automatic filter changes, ensuring maximum flexibility and ease of use. The shortage of confocal microscope time has become a major problem over the last three years. Since the CBI commenced operations 5 years ago, it has become an integral part of the medical research community participating in research projects with more than 50 PHS funded groups within the medical area. Confocal microscopy is an essential service provided by the center. However, as the PHS funded user base continues to expand a lack Of available time on the CLSM has become a major limiting factor in the utility of the center. This leads to considerable frustration amongst users, particularly because no other confocal microscopes are available. Furthermore, because of the overload of users, students are unable to get any time on the instrument at all. The acquisition of the requested instrument will allow individual users more ready access to confocal microscopy such that the user bottle neck for the current instrument will be resolved.